This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Expression of enzymes involved in glycoprotein biosynthesis for structural analysis by NMR and X-ray crystallography is being optimized in mammalian (HEK293) cells. High yield expression was previously accomplished in Pichia pastoris and 15N- 13C-, and 2H-labeling methods were achieved at low levels. Expression of several recombinant enzymes in HEK293 cells has also been accomplished and several of the proteins are entering screening for crystallization conditions.